New testcase distilled from a large chunk of code Misha sent me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22347 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/2005-07-07-DeadPHILoop.ll

@@ -0,0 +1,13 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+
+; This example caused instcombine to spin into an infinite loop.
+
+void %test(int *%P) {
+	ret void
+Dead:
+	%X = phi int [%Y, %Dead]
+	%Y = div int %X, 10
+	store int %Y, int* %P
+	br label %Dead
+}
+